Move `legal_instruments` code to new repo

[aibakeneko]

• [x] Create new repo
• [x] Add legal_instruments code to new repo
• [x] Add legal_instruments data to new repo
• [x] Remove legal_instruments
  • [x] Code
  • [x] Data
  • [x] Tests
  • [x] Dependencies
  • [x] Makefile recipes
  • [x] Settings
  • [x] README text

[aibakeneko]

Code related to collecting SSI (legal instruments) corpus data from the UNESCO website has been moved to https://github.com/inidun/legal_instruments.